1. Field of the Invention
The present invention relates to an image forming apparatus for developing an electrostatic latent image, using a magnetic toner.
2. Description of the Related Art
In recent years, there have been known image forming apparatuses constructed in such a manner that an RFID (Radio Frequency Identification) tag is attached to a developing unit, as a developing-unit-side RFID tag, and another RFID tag is attached to a toner cartridge for supplying toner to the developing unit, as a toner-cartridge-side RFID tag to communicate various data between the RFID tags. In the conventional image forming apparatuses, the toner-cartridge-side RFID tag is attached to an upper surface of an upper cover of the toner cartridge, and the developing-unit-side RFID tag is attached to a bottom wall of a toner cartridge mounting portion for mounting the toner cartridge therein.
Japanese Unexamined Patent Publication No. 2003-271042 discloses a wireless communication system constructed in such a manner that an RFID tag is provided in a space between an upper end portion of a cartridge component, and a main body of an image forming apparatus, or a space between a lower end portion of the cartridge component and the apparatus main body; and a main-body-side antenna is provided sufficiently close to an RFID-tag-side antenna to perform desirable communication between the RFID tag as a wireless communication device, and the apparatus main body.
The height of the magnetic toner contained in the toner cartridge is lowered, as the magnetic toner is consumed, and the magnetic toner flies within the space of the toner cartridge, with the result that the toner may adhere to the inner walls or the upper cover of the toner cartridge. As a result, a magnetic field between the toner-cartridge-side RFID tag and the developing-unit-side RFID tag is greatly fluctuated, which obstructs stable communication between the two RFID tags i.e. wireless communication devices. Further, the wireless communication system recited in the above publication is provided to perform desirable communication between the wireless communication device and the apparatus main body, and is not motivated to eliminate a fluctuation of the magnetic field by the magnetic toner.